I'm sorry you got this type of news and this doesn't change the person you are. You'll just have to be careful and monitor yourself if you ever have outbreaks.
Okay, let's look at the dates you've posted. You've been w/your h since 1996 and had a child later. You also indicated that you didn't have any STD's or herpes when you were tested back then...so, I may be wrong about this, but I would have to ask myself if it was possible that you contracted this from your h, if you haven't been w/anyone in the last 18-20 years. I hope I'm wrong about this and him.
From what you've indicated, your h isn't too concerned about the matter and that really does send red flags up for me. Most people would be floored to know that 1) they have this; and 2) their partners may have gotten it from me. Your h doesn't appear to be bothered one way or another. Could this be the reason he's not wanting to get tested?
You may be one of the few lucky ones that won't have an outbreak, but I would ask my Dr. about it and learn as much as you can and I would also ask if stress may affect this. Then again, your test may not be accurate. I would have it repeated again just to make sure....again, ask your Dr.
Breathe and remember, you are a good person and this shouldn't affect how you move forward; and like woundedfool stated, if you have been w/someone recently, they would need to be advised of the situation...but those 20 years ago...there is very little merit in doing so.